Pigtail-brush.



J. HETHERINGTON 61 C. E. CHAPIN.

, PIGTAIL BRUSHL 7 APPLICATION r1150 JAN-17.1911. RENEWED MAY 1.1915.

Patented Sept. 28, 1915.

eff/21 1516 7 z/Zvwmawr UNITED STATES PATENT OFFICE.

J'OHN HETHERINGTON, F NEWARK, NEW JERSEY, AND CHARLES E. CHAPIN, OF NEWYORK, N. Y.; SAID HETHERINGTON ASSIGNOR TO SAID CHAPIN.

PIGTAIL-BRUSH.

Specification of Letters Patent.

Patented Sept. 28, 1915.

Application filed January 17, 1911, Serial No. 603,063. Renewed May 1,1915. Serial No.-25,308.

To all whom it may concern:

Be it known that we, JoHN HETHERING- TON and CHARLES E. CIIAPIN,citizens of the United States, v residing, respectively, at

Newark, New Jersey, and New York, N. Y have-invented certain new anduseful Improvements in Pigtail Brushes, of which the following'is aclear, full, and exact descriptiq'n. v

This invention relates to an improved con nection between6l8CtI'ICQl-lYCOIIdHCtIIIg members, as for instance the'connection in apigtail brush usually employed in dynamos and the like. i

The object of this invention is to provide a connection which may besecurely locked with ordinary tools, such as are always at hand, andwhich will remain looked under all ordinary conditions of use, but whichwhen necessary. may be unfastened' by an ordinary tool, such as ascrew-driver. In the illustrated preferred embodiment we have shown thisconnection as employed in the ordinary pigtail carbon brush of a dynamo.7

We do not wish our invention to be limited to the specific. formdisclosed in the present case, as various modifications may be -made inthe same without departing from the spirit of our invention as broadlyembodied n the appended claims.

In t e preferred embodiment of ourinvention shown in the drawings,Figure 1 is a perspective view of the ordinary pigtail conductor cablewhich is to be connected to said block. As shown in Fig. 3, the block 1has an orifice 12 therethrough with a recess 7 at one side thereof.Extending through the orifice 12 of block 1 is a terminal post 3 havinga slotted head t at one, end thereof .and a threaded portion 8 at theother end thereof adapted to receive a threaded cap 5 screwed thereon.As shown in Fig.24 the 5 is countersunk or recessed at 8 fora par-'tlcular purpose which will now be described. 'After the parts have beenassembled as shown in Fig. 2 and the cap 5 is screwed tightly down uponthe terminal 6, it is desirable to lock the parts in this position sothat they will not become unfastened under the ordinary conditions ofuse. To do this any round pointed tool inserted in the countersunk endof the post 3 and tapped with a hammer so as to jam the thin threadedwalls of the countersunk portion 8 into the thread of the cap 5 and alsoupset edge of said threaded walls over the outside face of said cap. Theend of the post 3 being thus jammed into the thread of cap 5 and itsedge upset as described, the cap will thus be prevented from workingloose of itself, but yet when it is desired to disassemble the parts forreplacing any particular portion a screw-driver may be applied in theslot of cap 5 and also in slot 11 of head 4: to'

unscrew said cap, the metal of the wall 8 being soft and pliable enoughto permit such action by hand, and without destroying the integrity ofthe threads of the post.

It will thus be seen that We have provided a terminal connection whichwill not won loose under ordinary conditions of use yet which can beloosened if necessary without the use of any particular tools.

\Vhat we claim new is:

1. A pig-tail brush comprising a block of easily frangible conductingmaterial, such as carbon, having a hole therethrough, a terminal posthaving a headbearing upon one side of said block and a threaded shankextending through said hole, a metallic conductor having a terminalportion surrounding said shank, and a nut screwed upon said shank andpressing said conductor terminal tightly against said block, said shankbeing constructed to be expanded within but not below said nut intolocking relation to said nut by pressure exerted within the periph- Icry of said shank, whereby no strains either of vertical or of lateralpressure or: shock are left in said block.

2. A pig-tail brush comprising a block of easily frangible conductingmaterial, such as carbon, having a hole therethrough, a terminal posthaving a head bearing upon one side of said block and having a threadedshank extending through said hole and hollowed out at its end Withinsaid threaded portion to provide a relatively thin threadcarrying wall,a flexible conductor having a terminal portion surrounding said shank,

and a nut screwed upon said shank and pressing said conductor terminal,tightly against-said block, said thread-carrying wall being outwardlyforced in and above said nut into retaining relation thereto.

3. A 'pigtail brush comprising a block of easily frangible conductingmaterial such as carbon having a hole therethrough near one end andwith. a recess in said block larger than said hole at each end thereofand having a lateral hollowed extension from one of said recessesthrough one side of said block, a metallic terminal post extendingthrough and fitting in said hole in said block and having a head lyingin and wholly contained in the recess atone side of said block, saidpost having'a screw-threaded end lying substantially within the recessat the other side of said block, a flexible conductor having a terminalportion lying in said latter recess and the said lateral extension fromsaid recess and surrounding said terminal post, a nut having a threadedhole therein and screwed upon the threaded end of said post over saidlatter terminal and holding the same upon the bottom of said recess andentirely inclosed Within said recess, the threaded end of said terminalpost being hollowed out whereby a relatively thin wall is left at theextreme upper edge of said terminal post, the metal of said thin wall atthe extreme upper end of said post being outwardly forced whereby thepressure exerted by said outwardly upset end is transmitted to said nutin a direction radial to said post.

4. A pigtail brush comprising a block of easily frangible conductingmaterial such as carbon, having a hole therethrough near one end andwitha recess in said block larger than said hole at each end thereof andhaving a lateral hollowed extension. from one of said recesses throughone side of said block, a metallic terminal post extending through andfitting in said hole in said block and having a head lying in and whollycontained in the recess at one side of said block, said post having ascrew-threaded end lying substantially within the recess at the otherside of said block, a flexible conductor having a terminal portion lyingin said latter recess and the said lateral extension from said recessand surrounding said terminal post, a nut having a threaded hole thereinand screwed upon the threaded end of said post over said latter terminaland holding the same upon the bottom of said recess and entirelyinclosed within said recess, said nut having a slot in its upper facecommunicating with said hole in the nut, the threaded end of' saidterminal'post being hollowed out whereby a relatively thin Wall is leftat the extreme upper edge of said terminal post, the metal of said thinwall at the extreme upper end of said post being outwardly forced andpartly into the said slot in said nut, whereby the pressure exerted by.said outwardly upset end is transmitted to said nut in a directionradial to said post'and the metal forcedinto said slot locks the nutfrom accidentalremoval. Signed at New York city, N. Y., this 16th day ofJanuary, 1911.

JOHN HETHERINGTON. CHARLES E. GI-IAPIN.

Witnesses:

BEATRICE Minvis, ABRAM. BERNSTEIN.

